System, method and apparatus for servicing a pulverizer

ABSTRACT

A system for servicing a pulverizer includes a pulverizer having a housing, a journal assembly pivotally connected to the housing, a grinding mechanism operatively connected to the journal assembly, and an opening within the housing adjacent to the journal assembly and providing an access point to an interior of the housing, and a hoist apparatus mounted to the housing. The hoist apparatus includes a frame assembly received about the opening in the housing, a sheave assembly including a plurality of sheaves supported by the frame assembly, a motor operatively connected to one of the plurality of sheaves, and a cable received by the sheave assembly. The motor is operable to at least one of retract the cable through the sheave assembly to rotate a component out of the pulverizer through the opening and controllably let out the cable to rotate the component into the pulverizer through the opening.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to, and is a divisional of U.S.Non-Provisional application Ser. No. 15/142,062, filed on Apr. 29, 2016and titled “SYSTEM, METHOD AND APPARATUS FOR SERVICING A PULVERIZER,”which is incorporated herein by reference in its entirety.

BACKGROUND Technical Field

Embodiments of the invention relate to pulverized coal boilers and, moreparticularly, to a system, method and apparatus for servicing and/orreplacing grinding assembly components of a pulverizer.

DISCUSSION OF ART

Coal fired boilers utilize pulverizers, such as, for example, bowl millpulverizers, to grind coal to a desired fineness so that it may be usedas fuel for burners. In a typical pulverized coal boiler, coalparticulate and primary air flow from the pulverizers to the burnersthrough an array of coal pipes leading from the pulverizers to theburners. Typically, raw coal is fed through a central coal inlet at thetop of the pulverizer and falls by gravity to a grinding table at thebase of the mill. Grinding rollers mounted on suitably supportedjournals interact with the grinding table to effect the grinding ofmaterial interposed therebetween. After being pulverized, the particlesof material are transported upwards using air as the transport medium.Once the coal is ground finely enough, it is discharged from thepulverizer and distributed among multiple pulverized coal outlet pipesand into respective fuel conduits where it is carried to the burners.

Over time, the grinding elements of the pulverizer exhibit wear andultimately require replacement. Replacement of the grinding elementsrequires that they be removed from the pulverizer. Certain pulverizersare designed so that the journal assembly and the grinding roll of thegrinding assembly can be rotated out of the pulverizer housing so thatreplacement and/or maintenance can be performed. This design, however,requires that a large and complex crane system that runs the length ofthe mill bay be installed for every project.

In view of the above, there is a need for a system, method and apparatusthat enables the journal assembly and grinding roll assembly to berotated in or out of the pulverizer during replacement or servicingwithout the use of an overhead crane or fork lift.

BRIEF DESCRIPTION

In an embodiment a system for servicing a pulverizer is provided. Thesystem includes a pulverizer having a housing, a journal assemblypivotally connected to the housing, a grinding mechanism operativelyconnected to the journal assembly, an opening within the housingadjacent to the journal assembly and providing an access point to aninterior of the housing, and a plurality of holes in the housingsurrounding the opening configured to receive fasteners for selectivelysecuring a cover and a hoist apparatus to the housing, and the hoistapparatus mounted to the housing of the pulverizer. The hoist apparatusincludes a frame assembly received about the opening in the housing, asheave assembly including a plurality of sheaves supported by the frameassembly, the sheaves being mounted for rotation about respectivehorizontal axes, a motor operatively connected to one of the pluralityof sheaves, and a cable received by the sheave assembly. The motor isoperable to at least one of retract the cable through the sheaveassembly to rotate a component out of the pulverizer through the openingand controllably let out the cable to rotate the component into thepulverizer through the opening.

In another embodiment, a method for servicing a pulverizer is provided.The method includes the steps of connecting a hoist apparatus to thehousing of a pulverizer adjacent to a journal opening in the housing,extending a cable through the journal opening into the housing,connecting the cable to a component within the housing, actuating amotor of the hoist apparatus to rotate the sheave to withdraw the cable,and rotating the component out of the housing through the opening.

In yet another embodiment, a hoist apparatus for a pulverizer isprovided. The hoist apparatus includes a frame assembly having a backplate having a plurality of apertures configured to receive fastenersfor mounting the hoist apparatus to the pulverizer, a top plateextending outwardly from the back plate, and a plurality of supportplates extending between the back plate and the top plate and configuredto support the top plate from below, a sheave assembly including aplurality of sheaves supported by the frame assembly, the sheaves beingmounted for rotation about respective horizontal axes, a motoroperatively connected to one of the plurality of sheaves, and a cablereceived by the sheave assembly. The motor is operable to retract thecable through the sheave assembly to rotate a component out of thepulverizer.

DRAWINGS

The present invention will be better understood from reading thefollowing description of non-limiting embodiments, with reference to theattached drawings, wherein below:

FIG. 1 is a front, perspective view of a hoist apparatus for servicingthe grinding mechanism of a pulverizer, according to an embodiment ofthe invention.

FIG. 2 is a rear, perspective view of the hoist apparatus of FIG. 1 .

FIG. 3 is a perspective view of a frame assembly of the hoist apparatusof FIG. 1 .

FIG. 4 is front, elevational view of the frame assembly of FIG. 3 .

FIG. 5 is a right side, perspective view of the hoist apparatus of FIG.1 , shown installed on the housing of a pulverizer.

FIG. 6 is a left side, perspective view of the hoist apparatus of FIG. 1, shown installed on the housing of a pulverizer.

FIG. 7 is another right side, perspective view of the hoist apparatus,shown with an integral motor and attached to the housing of apulverizer.

FIG. 8 another left side, perspective view of the hoist apparatus, shownwith an integral motor and attached to the housing of a pulverizer.

FIG. 9 is a simplified, cross-sectional illustration of the hoistapparatus, shown attached to a pulverizer.

FIG. 10 a simplified, schematic illustration of the hoist apparatus,showing a tilt-out operation for removing a journal assembly andgrinding assembly of the pulverizer.

FIG. 11 a simplified, schematic illustration of the hoist apparatus,showing a tilt-in operation for installing a journal assembly andgrinding assembly of the pulverizer.

DETAILED DESCRIPTION

Reference will be made below in detail to exemplary embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference characters usedthroughout the drawings refer to the same or like parts. Whileembodiments of the invention are directed to an apparatus and method fortilting or lifting a journal assembly and grinding mechanism out of thehousing of a pulverizer, embodiments of the invention may also beapplicable for lifting or removing other internal components of apulverizer or grinding mill. In addition, embodiments of the inventionmay also be applicable for lifting items or components, more generally.

As used herein, “operatively coupled” refers to a connection, which maybe direct or indirect. The connection is not necessarily being amechanical attachment. As used herein, “mechanically coupled” refers toany coupling method capable of supporting the necessary forces fortransmitting torque between components.

Embodiments of the invention relate to a hoist apparatus and method fortilting or lifting a journal assembly and grinding mechanism out of thehousing of a pulverizer so that the journal assembly or grindingassembly may be repaired or replaced. With reference to FIGS. 1-4 , ahoist apparatus 10 according to an embodiment of the invention includesa frame assembly 12 having a generally U-shaped back plate 14 formedfrom a pair of opposed, vertical leg members 16 and a cross member 18connecting the leg members 16 at respective top ends thereof. The frameassembly 12 also includes a top plate 20 that extends outward from thecross member 18 of the back plate at an upward angle. A pair of opposedbolstering members or support plates 22 extend between the respectiveleg members 16 and the top plate 20 and support the top plate 20 frombelow. As best shown in FIG. 4 , the support plates 22 angle inward fromthe back plate 14 to the top plate 20. In an embodiment, the back plate,top plate and supporting plates may be formed from stamped or cut platesof metal and are joined together by welding, although other joiningmeans such as bolts or threaded fasteners may be utilized withoutdeparting from the broader aspects of the present invention. In otherembodiments, one or more of these components may be a single casting.

In an embodiment, the hoist apparatus 10 may also include a ballastweight 24. The ballast weight may be welded or otherwise fastened to theback face of the back plate 14 and, in particular, to the back face ofthe cross member 18 of the back plate, the purpose of which will bediscussed hereinafter.

As shown in FIGS. 1 and 2 , the hoist apparatus 10 also includes aplurality of sheaves configured to receive a wire rope or cable. Forexample, as shown therein, a first sheave 26 is mounted to the top plate20 via a mounting block 28. In addition, three additional sheaves 30,32, 34 are mounted beneath the top plate 20. Each of the sheaves 26, 30,32, 34 are mounted for rotation about respective horizontal axes and arepositioned along a center line of the frame assembly 12 when viewed fromthe front.

Turning now to FIGS. 5 and 6 , the hoist apparatus 10 is shown inposition with respect to the housing of a pulverizer 100. In anillustrative embodiment, the pulverizer 100 may be a verticalspindle-type pulverizer that includes a pulverizer housing 104 withinwhich a grinding table (not shown) is situated to provide a grindingsurface for a material to be pulverized. In one embodiment, the grindingtable is mounted on a shaft (not shown) that in turn is operativelyconnected to a suitable gearbox drive mechanism (not shown) so as to becapable of being suitably driven for rotation within the pulverizerhousing 104. As is known in the art, a journal assembly 109 is pivotablymounted on a pivot shaft 108 that is secured to the pulverizer housing106. The journal assembly 109 carries a grinding roll 110 rotatablymounted thereon for grinding a material such as raw coal. As indicatedabove, once coal is ground to a desired degree of fineness, it istransported upward by a flow of primary air, through a classifiersection, and exits the pulverizer 100 through a plurality of coal outletpipes 112. While a vertical spindle type pulverizer is shown anddescribed herein, the apparatus 10 of the invention may also be usedwith other types of pulverizers without departing from the broaderaspects of the present invention.

As shown in FIGS. 5 and 6 , the frame assembly 12 of the apparatus 10 isdimensioned to correspond to the size of a journal opening 102 in thehousing 104 of the pulverizer. As illustrated therein, the ballastweight 24 of the apparatus 10 is configured to rest atop the frame 106which defines the journal opening 102. Once positioned around theopening 102, the hoist apparatus 10 may be secured to the front face ofthe frame by bolts or other fasteners. In this position, the sheaves 26,30, 32, 34 are centered with respect to the journal opening 102. In anembodiment, the apparatus 10 may be secured to the pulverizer 100 aboutthe journal opening 102 via the existing journal opening cover boltholes 103. This eliminates any need to modify or alter the pulverizeritself to accommodate the hoist apparatus 10. In connection with this,the frame of the journal opening 102 may include one or more bolts orpins (e.g., bolts installed in one or more of the existing journalopening cover holes) that serve as guides or aligning features forlining up the holes in the frame of the hoist apparatus 10 to the boltholes in the housing 104 of the pulverizer 100.

With reference to FIGS. 7 and 8 , in an embodiment, the hoist apparatus10 includes a motor 36 having a rotating output shaft connected to thesheave 26. For example, the motor 36 may be mounted and supported by oneor more of the mounting block 28 of the sheave 26 and/or the top plate20 of the frame assembly 12. The motor 36 is configured to rotate thesheave 26 to effect winding of the wire rope 40, as discussed in detailhereinafter. In particular, with reference to FIGS. 9-11 , when it isdesired to service or replace any part of the journal assembly 109 orgrinding mechanism (e.g., a grinding roll 110), the journal opening 102is first accessed by removing a door or panel. The hoist apparatus 10may then be mounted to the frame 106 of the opening 102 in the mannerhereinbefore described. The wire rope 40 is then attached to a point onthe journal assembly 109 or grinding mechanism. Actuation of the motor36 reels in the wire rope 40, causing the journal assembly 109 andgrinding mechanism to rotate out of the housing 106 through the journalopening 102. In this position, as illustrated in FIGS. 10 and 11 , thejournal assembly 109 and the grinding mechanism are accessible so thatservice, maintenance or replacement operations may be performed. Oncecomplete, the motor 36 may be utilized to slowly rotate the journalassembly 109 and grinding mechanism back into place within the housing106. In an embodiment, the motor 36 may be a hydraulic motor or anelectric motor.

Due to the relatively small size and weight of the hoist apparatus 10,the apparatus 10 may be moved from journal opening to journal opening,or from pulverizer to pulverizer, quickly and easily whenevermaintenance or replacement of the journal assembly, grinding mechanismor other components of a pulverizer is necessary. In an embodiment, theweight of the apparatus 10 is between about 1,000 pounds to about30,000. In an embodiment, the weight of the apparatus 10 is betweenabout 6,000 pounds and 25,000 pounds depending on the materials used andthe size of the pulverizer with which the apparatus is intended to beutilized.

The apparatus 10 is also compact, allowing it to be utilized insituations even where there is limited space around the pulverizer dueto piping and platforms. In particular, as best illustrated in FIG. 9 ,the top of the apparatus 10 does not extend substantially above a topsurface of a turret, also referred to as the mill outlet area, of thepulverizer 100 (i.e., the top of the surface of the apparatus 10 extendsroughly to, or below, a height equal to where the coal outlet pipes 112are joined to the turret). The sheaves 26, 30, 32, 34 are also designedand so located so as to minimize the total height of the apparatus 10.This low-profile configuration helps to minimize weight as well asreduce the likelihood of interference with anything above the apparatus(such as maintenance platforms on certain pulverizers). Moreover, thesheaves area arranged to allow the cable 40 to clear the top of thejournal opening 102 during tilt out and tilt in, and to keep the angleof the cable 40 as wide as possible to minimize the load on the sheaves,shafts and frame. The location of the motor 36 (and sheave 26) is basedon a minimum fleet distance, the angle of the cable 40 on the leadingsheave, and the desire to keep the height of the apparatus 10 as low aspossible. In an embodiment, it is also desirable from a structuralstandpoint that the motor 36 and leading sheave is located close to thebody of the pulverizer 100.

In addition to the above, the apparatus 10 is configured such that itmay be utilized with existing pulverizers without modification to thepulverizer or its surroundings. As best shown in FIG. 9 , the reevingarrangement is arranged in such a way as to locate the journal center ofgravity in a precise location as the journal is tilted out. Thislocation is set so that the center of gravity is within a specifieddistance of the pivot center point when the wire rope 40 is at itsshortest length. This allows the wire rope or cable 40 to be slowlyreleased and journal slowly set down in its resting position. In anembodiment, the sheaves 26, 30, 32, 34 are arranged in such a manner sothat when the journal is tilted in or out, the center of gravity islocated approximately 1-2″ beyond a horizontal plane defined by thejournal pivot center when the cable 40 is at its shortest length. Forexample, when the journal is being tilted out and the cable 40 is at itsshortest length, the center of gravity of the journal is 1-2″ outside ofthe journal pivot, allowing the direction of the hoist to be simplyreversed and the journal lowered. When the journal is tilted in, theopposite of the above would be true. This configuration functions tominimize any accelerations or falls of the journal during tilt out. Inan embodiment, the linear distance between the axis of rotation ofsheave 26 and the axis of rotation of sheave 30 is approximately 49.42inches. In an embodiment, the sheave tread diameter for sheaves 30, 32,34 is approximately 10.62 inches. In an embodiment, the dimensions andratios of apparatus height, width, sheave location and the like arebased on a bowl diameter of the pulverizer 100. The embodiments of theapparatus 10 described herein are based on a 120 inch bowl.

As discussed above, in an embodiment, the hoist apparatus 10 includes aballast weight 24 that serves to locate the center of gravity of theapparatus 10 in a location where a crane, forklift or other device canlift the apparatus 10 into position surrounding the journal opening 102without requiring additional rigging or the like. In other embodiments,the hoist assembly 10 may be integrated into a height-adjustable castersto allow the apparatus 10 to be rolled into place without the use ofother machinery.

As indicated above, the hoist apparatus 10, in contrast to existingsystems and methods, does not require modification to the mill itssurroundings and can be easily retrofit onto existing mills. Inaddition, no additional support equipment such as cranes or forklifts istypically necessary to install the apparatus 10. In contrast to existingmethods, the hoist apparatus 10 of the invention can be manufactured ata low cost, due to a limited number of components required. Moreover,because of a limited number of moving parts, required maintenance of theapparatus 10 may be negligible. The apparatus 10 may also allow for areduced amount of man hours required to remove or service pulverizercomponents such as a journal assembly or grinding mechanism as comparedto existing systems and methods.

In an embodiment a system for servicing a pulverizer is provided. Thesystem includes a pulverizer having a housing, a journal assemblypivotally connected to the housing, a grinding mechanism operativelyconnected to the journal assembly, and an opening within the housingadjacent to the journal assembly and providing an access point to aninterior of the housing, and a hoist apparatus mounted to the housing ofthe pulverizer. The hoist apparatus includes a frame assembly receivedabout the opening in the housing, a sheave assembly including aplurality of sheaves supported by the frame assembly, the sheaves beingmounted for rotation about respective horizontal axes, a motoroperatively connected to one of the plurality of sheaves, and a cablereceived by the sheave assembly. The motor is operable to at least oneof retract the cable through the sheave assembly to rotate a componentout of the pulverizer through the opening and controllably let out thecable to rotate the component into the pulverizer through the opening.In an embodiment, the hoist apparatus is secured to the housing of thepulverizer using cover bolt holes in the housing that surround theopening. In an embodiment, the pulverizer includes a turret, and thehoist apparatus is located substantially below a plane defined by a topsurface of the turret. In an embodiment, the hoist apparatus weighsbetween about 1,000 pounds and 30,000 pounds. In an embodiment, thecomponent is the grinding mechanism. In an embodiment, the component isthe journal assembly. In an embodiment, the plurality of sheaves arelocated such that a center of gravity of the journal assembly is about 0inches to about 6 inches outside of a pivot point of the journalassembly when the journal assembly is rotated out of the opening and thecable is at its shortest length. In other embodiments, the plurality ofsheaves are located such that a center of gravity of the journalassembly is about 0 inches to about 6 inches outside of the pivot pointof the journal assembly when the journal assembly is rotated out of theopening and the cable is at its shortest length. In an embodiment, thesheaves are located so that the cable does not contact a top of theopening during retraction or letting out of the cable.

In another embodiment, a method for servicing a pulverizer is provided.The method includes the steps of connecting a hoist apparatus to thehousing of a pulverizer adjacent to a journal opening in the housing,extending a cable through the journal opening into the housing,connecting the cable to a component within the housing, and actuating amotor of the hoist apparatus to withdraw the cable and rotate thecomponent out of the housing through the opening. In an embodiment, themethod may also include the step of removing a cover to expose thejournal opening, wherein the hoist apparatus is connected to the housingusing bolt holes surrounding the journal opening that are utilized tosecure the cover over the journal opening. In an embodiment, thecomponent is a journal assembly. In an embodiment, the component is agrinding mechanism. In an embodiment, the pulverizer includes a turret,wherein when mounted to the housing, the hoist apparatus is locatedsubstantially below a plane defined by a top surface of the turret. Inan embodiment, the hoist apparatus weighs between about 1,000 pounds and30,000 pounds. In an embodiment, the hoist apparatus includes aplurality of sheaves that receive the cable, the plurality of sheavesbeing located such that a center of gravity of the journal assembly isapproximately 0 inches to 6 inches outside of a pivot point of thejournal assembly when the journal assembly is rotated out of the openingand the cable is at its shortest length.

In yet another embodiment, a hoist apparatus for a pulverizer isprovided. The hoist apparatus includes a frame assembly having a backplate, a top plate extending outwardly from the back plate, and aplurality of support plates extending between the back plate and the topplate and configured to support the top plate from below, a sheaveassembly including a plurality of sheaves supported by the frameassembly, the sheaves being mounted for rotation about respectivehorizontal axes, a motor operatively connected to one of the pluralityof sheaves, and a cable received by the sheave assembly. The motor isoperable to retract the cable through the sheave assembly to rotate acomponent out of the pulverizer. In an embodiment, the hoist apparatusmay further include a ballast connected to the back plate. In anembodiment, the sheave to which the motor is connected is supported bythe top plate. In an embodiment, the top plate extends outward from theback plate at an upward angle. In an embodiment, the component is one ofjournal assembly and a grinding roll of the pulverizer.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the inventionwithout departing from its scope. While the dimensions and types ofmaterials described herein are intended to define the parameters of theinvention, they are by no means limiting and are exemplary embodiments.Many other embodiments will be apparent to those of skill in the artupon reviewing the above description. The scope of the invention should,therefore, be determined with reference to the appended claims, alongwith the full scope of equivalents to which such claims are entitled. Inthe appended claims, the terms “including” and “in which” are used asthe plain-English equivalents of the respective terms “comprising” and“wherein.” Moreover, in the following claims, terms such as “first,”“second,” “third,” “upper,” “lower,” “bottom,” “top,” etc. are usedmerely as labels, and are not intended to impose numerical or positionalrequirements on their objects. Further, the limitations of the followingclaims are not written in means-plus-function format and are notintended to be interpreted based on 35 U.S.C. § 112, sixth paragraph,unless and until such claim limitations expressly use the phrase “meansfor” followed by a statement of function void of further structure.

This written description uses examples to disclose several embodimentsof the invention, including the best mode, and also to enable one ofordinary skill in the art to practice the embodiments of invention,including making and using any devices or systems and performing anyincorporated methods. The patentable scope of the invention is definedby the claims, and may include other examples that occur to one ofordinary skill in the art. Such other examples are intended to be withinthe scope of the claims if they have structural elements that do notdiffer from the literal language of the claims, or if they includeequivalent structural elements with insubstantial differences from theliteral languages of the claims.

As used herein, an element or step recited in the singular and proceededwith the word “a” or “an” should be understood as not excluding pluralof said elements or steps, unless such exclusion is explicitly stated.Furthermore, references to “one embodiment” of the present invention arenot intended to be interpreted as excluding the existence of additionalembodiments that also incorporate the recited features. Moreover, unlessexplicitly stated to the contrary, embodiments “comprising,”“including,” or “having” an element or a plurality of elements having aparticular property may include additional such elements not having thatproperty.

Since certain changes may be made in the above-described system andmethod without departing from the spirit and scope of the inventionherein involved, it is intended that all of the subject matter of theabove description or shown in the accompanying drawings shall beinterpreted merely as examples illustrating the inventive concept hereinand shall not be construed as limiting the invention.

What is claimed is:
 1. A hoist apparatus for servicing a pulverizerhaving a housing, a journal assembly pivotally connected to the housing,a grinding mechanism operatively connected to the journal assembly, ajournal opening within the housing adjacent to the journal assembly thatprovides an access point to an interior of the housing, and a pluralityof holes in the housing surrounding the opening, the hoist apparatuscomprising: a frame assembly received about the journal opening withinthe housing of the pulverizer, the frame assembly including a back platewith a plurality of apertures configured to receive fasteners formounting the frame assembly to the plurality of holes in the housing ofthe pulverizer, formed from a pair of spaced apart, opposed leg members,and a cross member extending between the leg members to connect a topend of each of the leg members with one another to provide the frameassembly with dimensions that correspond to a size of the journalopening within the housing of the pulverizer, a top plate extendingoutwardly from the cross member of the back plate away from the housingof the pulverizer, and a plurality of support plates coupled to the backplate and the top plate, each of the support plates extending betweenthe back plate and the top plate at a downward angle between the legmembers to support the top plate from below; a sheave assembly includinga plurality of sheaves supported by the frame assembly, the sheavesbeing mounted for rotation about respective horizontal axes; a motoroperatively connected to one of the plurality of sheaves; and a cablereceived by the sheave assembly; wherein the motor is operable to atleast one of retract the cable through the sheave assembly to rotate acomponent out of the pulverizer and controllably let out the cable torotate the component into the pulverizer.
 2. The hoist apparatus ofclaim 1, further comprising: a ballast connected to the back plate. 3.The hoist apparatus of claim 1, wherein: the sheave to which the motoris connected is supported by the top plate.
 4. The hoist apparatus ofclaim 1, wherein: the top plate extends outward from the back plate atan upward angle.
 5. The hoist apparatus of claim 1, wherein: thecomponent is one of the journal assembly and the grinding mechanism. 6.A method for servicing a pulverizer having a housing, a journal assemblypivotally connected to the housing, a grinding mechanism operativelyconnected to the journal assembly, a journal opening within the housingadjacent to the journal assembly that provides an access point to aninterior of the housing, and a plurality of holes in the housingsurrounding the opening, the method comprising the steps of: mounting ahoist apparatus to the housing of the pulverizer adjacent to the journalopening in the housing, the hoist apparatus including: a frame assemblyreceived about the journal opening within the housing of the pulverizer,the frame assembly including a back plate with a plurality of aperturesconfigured to receive fasteners for mounting the frame assembly to theplurality of holes in the housing of the pulverizer, formed from a pairof spaced apart, opposed leg members, and a cross member extendingbetween the leg members to connect a top end of each of the leg memberswith one another to provide the frame assembly with dimensions thatcorrespond to a size of the journal opening within the housing, a topplate extending outwardly from the cross member of the back plate awayfrom the housing of the pulverizer, and a plurality of support platescoupled to the back plate and the top plate, each of the support platesextending between the back plate and the top plate at a downward anglebetween the leg members to support the top plate from below; a sheaveassembly including a plurality of sheaves supported by the frameassembly, the sheaves being mounted for rotation about respectivehorizontal axes; a motor operatively connected to one of the pluralityof sheaves; and a cable received by the sheave assembly; extending thecable from a sheave of the sheave assembly in the hoist apparatusthrough the journal opening into the housing of the pulverizer;connecting the cable to a component within the housing; actuating themotor of the hoist apparatus to rotate the sheave to withdraw the cable;and rotating the component out of the housing through the opening. 7.The method according to claim 6, further comprising the step of:removing a cover to expose the journal opening and bolt holessurrounding the journal opening; and connecting the hoist apparatus tothe housing using the bolt holes surrounding the journal opening thatare utilized to secure the cover over the journal opening.
 8. The methodaccording to claim 7, wherein: the component is the journal assembly. 9.The method of claim 8, wherein: the plurality of sheaves are locatedsuch that a center of gravity of the journal assembly is approximately 0inch to 6 inches outside of a pivot point of the journal assembly whenthe journal assembly is rotated out of the journal opening and the cableis at its shortest length.
 10. The method according to claim 7, wherein:the component is the grinding mechanism.
 11. The method according toclaim 6, wherein: the pulverizer further includes a turret; and whereinwhen mounted to the housing, the hoist apparatus is locatedsubstantially below a plane defined by a top surface of the turret. 12.The method of claim 1, wherein: the hoist apparatus weighs between about1,000 pounds and 30,000 pounds.